NewScientist reports that a study confirms that others are largely able to guess your personality traits based solely on your email address--but the article doesn't offer any clues as to which features match which quirks.
But never fear: I was leaked an advance copy of the study, and will condense the results below.
An address that includes your name signifies narcissism.
A free service means you are a cheap bastard.
Punctuation indicates punctiliousness. And also narcissism.
Your soul has been in corporate cold storage for several years now.
You are a 12-year-old girl.
Openness and narcissism in equal doses, with a dash of pretense and a sprig of condescension.